If youre looking to upgrade the flight controller and add GPS capability on your AeroSky quad look no further, introducing the all in one upgrade kit from AeroSky. Mega 2.52 is a complete open source autopilot system featuring the bestselling technology. This version is ready to use, with no assembly required. It allows the user to turn any fixed wing, rotary wing or multi-rotor vehicle (even boats and car) into a fully autonomous vehicle capable of performing programmed GPS missions with waypoints.

Specifications for the flight controller:
 Arduino Compatible
 pre-soldered and tested
 3-axis gyro, accelerometer, magnetometer and high-performance barometer
 Built in 4 MP Dataflash chip for automatic data logging
 Honeywell HMC5883L-TR Digital compass
 Invensense's 6 DoF Accelerometer/Gyro MPU-6000
 Measurement Specialties MS5611-01BA03 Barometric pressure sensor.
 Atmel ATMEGA2560 and ATMEGA32U-2 (processing and USB function).
To set up your APM 2.5 board using the Arducopter codes please go to:https://code.google.com/p/arducopter/wiki/APM25boardSpecifications for the GPS module:
This is an updated GPS module that can used with ardupilot mega v2. This GPS module uses the latest technology to give the best possible position information, allowing for better performance with your Ardupilot or other Multirotor control platform.
You may require to configure this module for use with your flight controller (MultiWii Copter I2C GPS board requires 115200 baud). You will require a USB to FTDI adaptor board to do this.
Please note that this module ships with default settings and a buad rate of 38400.